diff --git a/src/JsonSchema/Constraints/FormatConstraint.php b/src/JsonSchema/Constraints/FormatConstraint.php
index 12c6a2bf..1a4f8492 100644
--- a/src/JsonSchema/Constraints/FormatConstraint.php
+++ b/src/JsonSchema/Constraints/FormatConstraint.php
@@ -8,7 +8,9 @@
  */
 
 namespace JsonSchema\Constraints;
+
 use JsonSchema\Rfc3339;
+use InvalidArgumentException;
 
 /**
  * Validates against the "format" property
@@ -18,6 +20,9 @@
  */
 class FormatConstraint extends Constraint
 {
+    protected $map = array(
+        'phone' => 'JsonSchema\Constraints\Validators\PhoneValidator'
+    );
     /**
      * {@inheritDoc}
      */
@@ -27,6 +32,15 @@ public function check($element, $schema = null, $path = null, $i = null)
             return;
         }
 
+        if(array_key_exists($schema->format, $this->map)) {
+            try {
+                (new $this->map[$schema->format])($element);
+            } catch(InvalidArgumentException $e) {
+                $this->addError($path, $e->getMessage(), 'format', array('format' => $schema->format,));
+            }
+            return;
+        }
+
         switch ($schema->format) {
             case 'date':
                 if (!$date = $this->validateDateTime($element, 'Y-m-d')) {
@@ -70,12 +84,6 @@ public function check($element, $schema = null, $path = null, $i = null)
                 }
                 break;
 
-            case 'phone':
-                if (!$this->validatePhone($element)) {
-                    $this->addError($path, "Invalid phone number", 'format', array('format' => $schema->format,));
-                }
-                break;
-
             case 'uri':
                 if (null === filter_var($element, FILTER_VALIDATE_URL, FILTER_NULL_ON_FAILURE)) {
                     $this->addError($path, "Invalid URL format", 'format', array('format' => $schema->format,));
@@ -154,11 +162,6 @@ protected function validateStyle($style)
         return empty($invalidEntries);
     }
 
-    protected function validatePhone($phone)
-    {
-        return preg_match('/^\+?(\(\d{3}\)|\d{3}) \d{3} \d{4}$/', $phone);
-    }
-
     protected function validateHostname($host)
     {
         return preg_match('/^[_a-z]+\.([_a-z]+\.?)+$/i', $host);
diff --git a/src/JsonSchema/Constraints/Validators/PhoneValidator.php b/src/JsonSchema/Constraints/Validators/PhoneValidator.php
new file mode 100644
index 00000000..919d41be
--- /dev/null
+++ b/src/JsonSchema/Constraints/Validators/PhoneValidator.php
@@ -0,0 +1,22 @@
+<?php
+
+/*
+ * This file is part of the JsonSchema package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JsonSchema\Constraints\Validators;
+
+use InvalidArgumentException;
+
+class PhoneValidator
+{
+  public function __invoke($element)
+  {
+    if(!preg_match('/^\+?(\(\d{3}\)|\d{3}) \d{3} \d{4}$/', $element)) {
+      throw new InvalidArgumentException('Invalid phone number');
+    }
+  }
+}
\ No newline at end of file